1. Field of Invention
The present invention relates to enhanced technology of an optical communication device (optical transceiver) to perform optical communication by using light.
2. Description of Related Art
Optical communication to perform information communication by using light as a carrier is one communication method which realizes high-speed and high-capacity communication. The construction of backbone networks and subscriber-system networks utilizing these features has become active in Japan and abroad. A terminal device on the subscriber side for the purpose of performing optical communication (for example, a personal computer) is provided with an optical communication device as an interface to transmit and receive optical signals.
A related art optical communication device may include components, such as a transmission section to convert an electrical signal carrying transmission information into an optical signal and transmitting the signal; a receiving section to convert an optical signal carrying received information into an electrical signal; and a connection section (optical connector) to optically connect an optical fiber with the transmission section or the receiving section.
In many optical communication devices, commonly called can packages a light-emitting element or a light-receiving element contained inside a metal housing is used. Such an optical communication device is disclosed in a document, for example, Japanese Unexamined Patent Application Publication No. 11-168233.
In recent years, the bandwidth of signals used for optical communication has begun to reach above several GHz to 10 GHz or higher, even in comparatively small networks such as LANs (Local Area Networks), and also in the optical communication devices, there has been an increasing demand for higher speed corresponding to such high-frequency transmission.
However, in an optical communication device using a can package, since the section between the can package and an electronic circuit to drive electro optical elements (light-emitting elements and light-receiving elements) contained in the can package is connected via metal terminals (metal pins) provided in the can package, transmission loss occurs in these metal terminals, and achieving higher speed has been difficult. The reason for this is that, since it is difficult to adjust the transmission characteristics, such as the characteristic impedance of metal terminals, reflection of the signal due to the impedance mismatch occurs in this portion, causing signal transmission to be obstructed. Such a problem becomes more conspicuous the higher the frequency of the signal to be transmitted becomes, and signal transmission becomes extremely difficult in the case of a high-frequency signal of several GHz or higher.
Accordingly, an advantage of the present invention is to provide an optical communication device suitable to transmit a high-frequency signal.